/* ** Generate code that will assemble an index key and stores it in register ** regOut. The key with be for index pIdx which is an index on pTab. ** iCur is the index of a cursor open on the pTab table and pointing to ** the entry that needs indexing. If pTab is a WITHOUT ROWID table, then ** iCur must be the cursor of the PRIMARY KEY index. ** ** Return a register number which is the first in a block of ** registers that holds the elements of the index key. The ** block of registers has already been deallocated by the time ** this routine returns. ** ** If *piPartIdxLabel is not NULL, fill it in with a label and jump ** to that label if pIdx is a partial index that should be skipped. ** A partial index should be skipped if its WHERE clause evaluates ** to false or null. If pIdx is not a partial index, *piPartIdxLabel ** will be set to zero which is an empty label that is ignored by ** sqlite3VdbeResolveLabel(). */ int sqlite3GenerateIndexKey( Parse *pParse, /* Parsing context */ Index *pIdx, /* The index for which to generate a key */ int iDataCur, /* Cursor number from which to take column data */ int regOut, /* Put the new key into this register if not 0 */ int prefixOnly, /* Compute only a unique prefix of the key */ int *piPartIdxLabel /* OUT: Jump to this label to skip partial index */ ){ Vdbe *v = pParse->pVdbe; int j; Table *pTab = pIdx->pTable; int regBase; int nCol; Index *pPk; if( piPartIdxLabel ){ if( pIdx->pPartIdxWhere ){ *piPartIdxLabel = sqlite3VdbeMakeLabel(v); pParse->iPartIdxTab = iDataCur; sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, SQLITE_JUMPIFNULL); }else{ *piPartIdxLabel = 0; } } nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn; regBase = sqlite3GetTempRange(pParse, nCol); pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab); for(j=0; j<nCol; j++){ i16 idx = pIdx->aiColumn[j]; if( pPk ) idx = sqlite3ColumnOfIndex(pPk, idx); if( idx<0 || idx==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regBase+j); }else{ sqlite3VdbeAddOp3(v, OP_Column, iDataCur, idx, regBase+j); sqlite3ColumnDefault(v, pTab, pIdx->aiColumn[j], -1); } } if( regOut ){ const char *zAff; if( pTab->pSelect || OptimizationDisabled(pParse->db, SQLITE_IdxRealAsInt) ){ zAff = 0; }else{ zAff = sqlite3IndexAffinityStr(v, pIdx); } sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut); sqlite3VdbeChangeP4(v, -1, zAff, P4_TRANSIENT); } sqlite3ReleaseTempRange(pParse, regBase, nCol); return regBase; }
/* ** Generate code that will assemble an index key and put it in register ** regOut. The key with be for index pIdx which is an index on pTab. ** iCur is the index of a cursor open on the pTab table and pointing to ** the entry that needs indexing. ** ** Return a register number which is the first in a block of ** registers that holds the elements of the index key. The ** block of registers has already been deallocated by the time ** this routine returns. ** ** If *piPartIdxLabel is not NULL, fill it in with a label and jump ** to that label if pIdx is a partial index that should be skipped. ** A partial index should be skipped if its WHERE clause evaluates ** to false or null. If pIdx is not a partial index, *piPartIdxLabel ** will be set to zero which is an empty label that is ignored by ** sqlite3VdbeResolveLabel(). */ int sqlite3GenerateIndexKey( Parse *pParse, /* Parsing context */ Index *pIdx, /* The index for which to generate a key */ int iCur, /* Cursor number for the pIdx->pTable table */ int regOut, /* Write the new index key to this register */ int doMakeRec, /* Run the OP_MakeRecord instruction if true */ int *piPartIdxLabel /* OUT: Jump to this label to skip partial index */ ){ Vdbe *v = pParse->pVdbe; int j; Table *pTab = pIdx->pTable; int regBase; int nCol; if( piPartIdxLabel ){ if( pIdx->pPartIdxWhere ){ *piPartIdxLabel = sqlite3VdbeMakeLabel(v); pParse->iPartIdxTab = iCur; sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, SQLITE_JUMPIFNULL); }else{ *piPartIdxLabel = 0; } } nCol = pIdx->nColumn; regBase = sqlite3GetTempRange(pParse, nCol+1); sqlite3VdbeAddOp2(v, OP_Rowid, iCur, regBase+nCol); for(j=0; j<nCol; j++){ int idx = pIdx->aiColumn[j]; if( idx==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_SCopy, regBase+nCol, regBase+j); }else{ sqlite3VdbeAddOp3(v, OP_Column, iCur, idx, regBase+j); sqlite3ColumnDefault(v, pTab, idx, -1); } } if( doMakeRec ){ const char *zAff; if( pTab->pSelect || OptimizationDisabled(pParse->db, SQLITE_IdxRealAsInt) ){ zAff = 0; }else{ zAff = sqlite3IndexAffinityStr(v, pIdx); } sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol+1, regOut); sqlite3VdbeChangeP4(v, -1, zAff, P4_TRANSIENT); } sqlite3ReleaseTempRange(pParse, regBase, nCol+1); return regBase; }
/* ** Generate code that will assemble an index key and stores it in register ** regOut. The key with be for index pIdx which is an index on pTab. ** iCur is the index of a cursor open on the pTab table and pointing to ** the entry that needs indexing. If pTab is a WITHOUT ROWID table, then ** iCur must be the cursor of the PRIMARY KEY index. ** ** Return a register number which is the first in a block of ** registers that holds the elements of the index key. The ** block of registers has already been deallocated by the time ** this routine returns. ** ** If *piPartIdxLabel is not NULL, fill it in with a label and jump ** to that label if pIdx is a partial index that should be skipped. ** The label should be resolved using sqlite3ResolvePartIdxLabel(). ** A partial index should be skipped if its WHERE clause evaluates ** to false or null. If pIdx is not a partial index, *piPartIdxLabel ** will be set to zero which is an empty label that is ignored by ** sqlite3ResolvePartIdxLabel(). ** ** The pPrior and regPrior parameters are used to implement a cache to ** avoid unnecessary register loads. If pPrior is not NULL, then it is ** a pointer to a different index for which an index key has just been ** computed into register regPrior. If the current pIdx index is generating ** its key into the same sequence of registers and if pPrior and pIdx share ** a column in common, then the register corresponding to that column already ** holds the correct value and the loading of that register is skipped. ** This optimization is helpful when doing a DELETE or an INTEGRITY_CHECK ** on a table with multiple indices, and especially with the ROWID or ** PRIMARY KEY columns of the index. */ int sqlite3GenerateIndexKey( Parse *pParse, /* Parsing context */ Index *pIdx, /* The index for which to generate a key */ int iDataCur, /* Cursor number from which to take column data */ int regOut, /* Put the new key into this register if not 0 */ int prefixOnly, /* Compute only a unique prefix of the key */ int *piPartIdxLabel, /* OUT: Jump to this label to skip partial index */ Index *pPrior, /* Previously generated index key */ int regPrior /* Register holding previous generated key */ ){ Vdbe *v = pParse->pVdbe; int j; Table *pTab = pIdx->pTable; int regBase; int nCol; if( piPartIdxLabel ){ if( pIdx->pPartIdxWhere ){ *piPartIdxLabel = sqlite3VdbeMakeLabel(v); pParse->iPartIdxTab = iDataCur; sqlite3ExprCachePush(pParse); sqlite3ExprIfFalse(pParse, pIdx->pPartIdxWhere, *piPartIdxLabel, SQLITE_JUMPIFNULL); }else{ *piPartIdxLabel = 0; } } nCol = (prefixOnly && pIdx->uniqNotNull) ? pIdx->nKeyCol : pIdx->nColumn; regBase = sqlite3GetTempRange(pParse, nCol); if( pPrior && (regBase!=regPrior || pPrior->pPartIdxWhere) ) pPrior = 0; for(j=0; j<nCol; j++){ if( pPrior && pPrior->aiColumn[j]==pIdx->aiColumn[j] ) continue; sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, pIdx->aiColumn[j], regBase+j); /* If the column affinity is REAL but the number is an integer, then it ** might be stored in the table as an integer (using a compact ** representation) then converted to REAL by an OP_RealAffinity opcode. ** But we are getting ready to store this value back into an index, where ** it should be converted by to INTEGER again. So omit the OP_RealAffinity ** opcode if it is present */ sqlite3VdbeDeletePriorOpcode(v, OP_RealAffinity); } if( regOut ){ sqlite3VdbeAddOp3(v, OP_MakeRecord, regBase, nCol, regOut); } sqlite3ReleaseTempRange(pParse, regBase, nCol); return regBase; }
/* ** This is called to code FOR EACH ROW triggers. ** ** When the code that this function generates is executed, the following ** must be true: ** ** 1. No cursors may be open in the main database. (But newIdx and oldIdx ** can be indices of cursors in temporary tables. See below.) ** ** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then ** a temporary vdbe cursor (index newIdx) must be open and pointing at ** a row containing values to be substituted for new.* expressions in the ** trigger program(s). ** ** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then ** a temporary vdbe cursor (index oldIdx) must be open and pointing at ** a row containing values to be substituted for old.* expressions in the ** trigger program(s). ** */ int sqlite3CodeRowTrigger( Parse *pParse, /* Parse context */ int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */ ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ int tr_tm, /* One of TK_BEFORE, TK_AFTER */ Table *pTab, /* The table to code triggers from */ int newIdx, /* The indice of the "new" row to access */ int oldIdx, /* The indice of the "old" row to access */ int orconf, /* ON CONFLICT policy */ int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ ){ Trigger * pTrigger; TriggerStack * pTriggerStack; assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); assert(tr_tm == TK_BEFORE || tr_tm == TK_AFTER ); assert(newIdx != -1 || oldIdx != -1); pTrigger = pTab->pTrigger; while( pTrigger ){ int fire_this = 0; /* determine whether we should code this trigger */ if( pTrigger->op == op && pTrigger->tr_tm == tr_tm && pTrigger->foreach == TK_ROW ){ fire_this = 1; pTriggerStack = pParse->trigStack; while( pTriggerStack ){ if( pTriggerStack->pTrigger == pTrigger ){ fire_this = 0; } pTriggerStack = pTriggerStack->pNext; } if( op == TK_UPDATE && pTrigger->pColumns && !checkColumnOverLap(pTrigger->pColumns, pChanges) ){ fire_this = 0; } } if( fire_this && (pTriggerStack = sqliteMalloc(sizeof(TriggerStack)))!=0 ){ int endTrigger; SrcList dummyTablist; Expr * whenExpr; AuthContext sContext; dummyTablist.nSrc = 0; /* Push an entry on to the trigger stack */ pTriggerStack->pTrigger = pTrigger; pTriggerStack->newIdx = newIdx; pTriggerStack->oldIdx = oldIdx; pTriggerStack->pTab = pTab; pTriggerStack->pNext = pParse->trigStack; pTriggerStack->ignoreJump = ignoreJump; pParse->trigStack = pTriggerStack; sqlite3AuthContextPush(pParse, &sContext, pTrigger->name); /* code the WHEN clause */ endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe); whenExpr = sqlite3ExprDup(pTrigger->pWhen); if( sqlite3ExprResolveIds(pParse, &dummyTablist, 0, whenExpr) ){ pParse->trigStack = pParse->trigStack->pNext; sqliteFree(pTriggerStack); sqlite3ExprDelete(whenExpr); return 1; } sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1); sqlite3ExprDelete(whenExpr); sqlite3VdbeAddOp(pParse->pVdbe, OP_ContextPush, 0, 0); codeTriggerProgram(pParse, pTrigger->step_list, orconf); sqlite3VdbeAddOp(pParse->pVdbe, OP_ContextPop, 0, 0); /* Pop the entry off the trigger stack */ pParse->trigStack = pParse->trigStack->pNext; sqlite3AuthContextPop(&sContext); sqliteFree(pTriggerStack); sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger); } pTrigger = pTrigger->pNext; } return 0; }
/* ** Create and populate a new TriggerPrg object with a sub-program ** implementing trigger pTrigger with ON CONFLICT policy orconf. */ static TriggerPrg *codeRowTrigger( Parse *pParse, /* Current parse context */ Trigger *pTrigger, /* Trigger to code */ Table *pTab, /* The table pTrigger is attached to */ int orconf /* ON CONFLICT policy to code trigger program with */ ){ Parse *pTop = sqlite3ParseToplevel(pParse); sqlite3 *db = pParse->db; /* Database handle */ TriggerPrg *pPrg; /* Value to return */ Expr *pWhen = 0; /* Duplicate of trigger WHEN expression */ Vdbe *v; /* Temporary VM */ NameContext sNC; /* Name context for sub-vdbe */ SubProgram *pProgram = 0; /* Sub-vdbe for trigger program */ Parse *pSubParse; /* Parse context for sub-vdbe */ int iEndTrigger = 0; /* Label to jump to if WHEN is false */ assert( pTrigger->zName==0 || pTab==tableOfTrigger(pTrigger) ); assert( pTop->pVdbe ); /* Allocate the TriggerPrg and SubProgram objects. To ensure that they ** are freed if an error occurs, link them into the Parse.pTriggerPrg ** list of the top-level Parse object sooner rather than later. */ pPrg = sqlite3DbMallocZero(db, sizeof(TriggerPrg)); if( !pPrg ) return 0; pPrg->pNext = pTop->pTriggerPrg; pTop->pTriggerPrg = pPrg; pPrg->pProgram = pProgram = sqlite3DbMallocZero(db, sizeof(SubProgram)); if( !pProgram ) return 0; sqlite3VdbeLinkSubProgram(pTop->pVdbe, pProgram); pPrg->pTrigger = pTrigger; pPrg->orconf = orconf; pPrg->aColmask[0] = 0xffffffff; pPrg->aColmask[1] = 0xffffffff; /* Allocate and populate a new Parse context to use for coding the ** trigger sub-program. */ pSubParse = sqlite3StackAllocZero(db, sizeof(Parse)); if( !pSubParse ) return 0; memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pSubParse; pSubParse->db = db; pSubParse->pTriggerTab = pTab; pSubParse->pToplevel = pTop; pSubParse->zAuthContext = pTrigger->zName; pSubParse->eTriggerOp = pTrigger->op; pSubParse->nQueryLoop = pParse->nQueryLoop; v = sqlite3GetVdbe(pSubParse); if( v ){ VdbeComment((v, "Start: %s.%s (%s %s%s%s ON %s)", pTrigger->zName, onErrorText(orconf), (pTrigger->tr_tm==TRIGGER_BEFORE ? "BEFORE" : "AFTER"), (pTrigger->op==TK_UPDATE ? "UPDATE" : ""), (pTrigger->op==TK_INSERT ? "INSERT" : ""), (pTrigger->op==TK_DELETE ? "DELETE" : ""), pTab->zName )); #ifndef SQLITE_OMIT_TRACE sqlite3VdbeChangeP4(v, -1, sqlite3MPrintf(db, "-- TRIGGER %s", pTrigger->zName), P4_DYNAMIC ); #endif /* If one was specified, code the WHEN clause. If it evaluates to false ** (or NULL) the sub-vdbe is immediately halted by jumping to the ** OP_Halt inserted at the end of the program. */ if( pTrigger->pWhen ){ pWhen = sqlite3ExprDup(db, pTrigger->pWhen, 0); if( SQLITE_OK==sqlite3ResolveExprNames(&sNC, pWhen) && db->mallocFailed==0 ){ iEndTrigger = sqlite3VdbeMakeLabel(v); sqlite3ExprIfFalse(pSubParse, pWhen, iEndTrigger, SQLITE_JUMPIFNULL); } sqlite3ExprDelete(db, pWhen); } /* Code the trigger program into the sub-vdbe. */ codeTriggerProgram(pSubParse, pTrigger->step_list, orconf); /* Insert an OP_Halt at the end of the sub-program. */ if( iEndTrigger ){ sqlite3VdbeResolveLabel(v, iEndTrigger); } sqlite3VdbeAddOp0(v, OP_Halt); VdbeComment((v, "End: %s.%s", pTrigger->zName, onErrorText(orconf))); transferParseError(pParse, pSubParse); if( db->mallocFailed==0 ){ pProgram->aOp = sqlite3VdbeTakeOpArray(v, &pProgram->nOp, &pTop->nMaxArg); } pProgram->nMem = pSubParse->nMem; pProgram->nCsr = pSubParse->nTab; pProgram->nOnce = pSubParse->nOnce; pProgram->token = (void *)pTrigger; pPrg->aColmask[0] = pSubParse->oldmask; pPrg->aColmask[1] = pSubParse->newmask; sqlite3VdbeDelete(v); } assert( !pSubParse->pAinc && !pSubParse->pZombieTab ); assert( !pSubParse->pTriggerPrg && !pSubParse->nMaxArg ); sqlite3StackFree(db, pSubParse); return pPrg; }
/* ** This is called to code FOR EACH ROW triggers. ** ** When the code that this function generates is executed, the following ** must be true: ** ** 1. No cursors may be open in the main database. (But newIdx and oldIdx ** can be indices of cursors in temporary tables. See below.) ** ** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then ** a temporary vdbe cursor (index newIdx) must be open and pointing at ** a row containing values to be substituted for new.* expressions in the ** trigger program(s). ** ** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then ** a temporary vdbe cursor (index oldIdx) must be open and pointing at ** a row containing values to be substituted for old.* expressions in the ** trigger program(s). ** */ int sqlite3CodeRowTrigger( Parse *pParse, /* Parse context */ int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */ ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ int tr_tm, /* One of TRIGGER_BEFORE, TRIGGER_AFTER */ Table *pTab, /* The table to code triggers from */ int newIdx, /* The indice of the "new" row to access */ int oldIdx, /* The indice of the "old" row to access */ int orconf, /* ON CONFLICT policy */ int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ ){ Trigger *p; TriggerStack trigStackEntry; assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER ); assert(newIdx != -1 || oldIdx != -1); for(p=pTab->pTrigger; p; p=p->pNext){ int fire_this = 0; sqlite3 *db = pParse->db; /* Determine whether we should code this trigger */ if( p->op==op && p->tr_tm==tr_tm && (p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema) && (op!=TK_UPDATE||!p->pColumns||checkColumnOverLap(p->pColumns,pChanges)) ){ TriggerStack *pS; /* Pointer to trigger-stack entry */ for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){} if( !pS ){ fire_this = 1; } #if 0 /* Give no warning for recursive triggers. Just do not do them */ else{ sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)", p->name); return SQLITE_ERROR; } #endif } if( fire_this ){ int endTrigger; Expr * whenExpr; AuthContext sContext; NameContext sNC; memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; /* Push an entry on to the trigger stack */ trigStackEntry.pTrigger = p; trigStackEntry.newIdx = newIdx; trigStackEntry.oldIdx = oldIdx; trigStackEntry.pTab = pTab; trigStackEntry.pNext = pParse->trigStack; trigStackEntry.ignoreJump = ignoreJump; pParse->trigStack = &trigStackEntry; sqlite3AuthContextPush(pParse, &sContext, p->name); /* code the WHEN clause */ endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe); whenExpr = sqlite3ExprDup(db, p->pWhen); if( db->mallocFailed || sqlite3ExprResolveNames(&sNC, whenExpr) ){ pParse->trigStack = trigStackEntry.pNext; sqlite3ExprDelete(whenExpr); return 1; } sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1); sqlite3ExprDelete(whenExpr); codeTriggerProgram(pParse, p->step_list, orconf); /* Pop the entry off the trigger stack */ pParse->trigStack = trigStackEntry.pNext; sqlite3AuthContextPop(&sContext); sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger); } } return 0; }
/* ** This is called to code FOR EACH ROW triggers. ** ** When the code that this function generates is executed, the following ** must be true: ** ** 1. No cursors may be open in the main database. (But newIdx and oldIdx ** can be indices of cursors in temporary tables. See below.) ** ** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then ** a temporary vdbe cursor (index newIdx) must be open and pointing at ** a row containing values to be substituted for new.* expressions in the ** trigger program(s). ** ** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then ** a temporary vdbe cursor (index oldIdx) must be open and pointing at ** a row containing values to be substituted for old.* expressions in the ** trigger program(s). ** ** If they are not NULL, the piOldColMask and piNewColMask output variables ** are set to values that describe the columns used by the trigger program ** in the OLD.* and NEW.* tables respectively. If column N of the ** pseudo-table is read at least once, the corresponding bit of the output ** mask is set. If a column with an index greater than 32 is read, the ** output mask is set to the special value 0xffffffff. ** */ int sqlite3CodeRowTrigger( Parse *pParse, /* Parse context */ Trigger *pTrigger, /* List of triggers on table pTab */ int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */ ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ int tr_tm, /* One of TRIGGER_BEFORE, TRIGGER_AFTER */ Table *pTab, /* The table to code triggers from */ int newIdx, /* The indice of the "new" row to access */ int oldIdx, /* The indice of the "old" row to access */ int orconf, /* ON CONFLICT policy */ int ignoreJump, /* Instruction to jump to for RAISE(IGNORE) */ u32 *piOldColMask, /* OUT: Mask of columns used from the OLD.* table */ u32 *piNewColMask /* OUT: Mask of columns used from the NEW.* table */ ){ Trigger *p; sqlite3 *db = pParse->db; TriggerStack trigStackEntry; trigStackEntry.oldColMask = 0; trigStackEntry.newColMask = 0; assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER ); assert(newIdx != -1 || oldIdx != -1); for(p=pTrigger; p; p=p->pNext){ int fire_this = 0; /* Sanity checking: The schema for the trigger and for the table are ** always defined. The trigger must be in the same schema as the table ** or else it must be a TEMP trigger. */ assert( p->pSchema!=0 ); assert( p->pTabSchema!=0 ); assert( p->pSchema==p->pTabSchema || p->pSchema==db->aDb[1].pSchema ); /* Determine whether we should code this trigger */ if( p->op==op && p->tr_tm==tr_tm && checkColumnOverlap(p->pColumns,pChanges) ){ TriggerStack *pS; /* Pointer to trigger-stack entry */ for(pS=pParse->trigStack; pS && p!=pS->pTrigger; pS=pS->pNext){} if( !pS ){ fire_this = 1; } #if 0 /* Give no warning for recursive triggers. Just do not do them */ else{ sqlite3ErrorMsg(pParse, "recursive triggers not supported (%s)", p->name); return SQLITE_ERROR; } #endif } if( fire_this ){ int endTrigger; Expr * whenExpr; AuthContext sContext; NameContext sNC; #ifndef SQLITE_OMIT_TRACE sqlite3VdbeAddOp4(pParse->pVdbe, OP_Trace, 0, 0, 0, sqlite3MPrintf(db, "-- TRIGGER %s", p->name), P4_DYNAMIC); #endif memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; /* Push an entry on to the trigger stack */ trigStackEntry.pTrigger = p; trigStackEntry.newIdx = newIdx; trigStackEntry.oldIdx = oldIdx; trigStackEntry.pTab = pTab; trigStackEntry.pNext = pParse->trigStack; trigStackEntry.ignoreJump = ignoreJump; pParse->trigStack = &trigStackEntry; sqlite3AuthContextPush(pParse, &sContext, p->name); /* code the WHEN clause */ endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe); whenExpr = sqlite3ExprDup(db, p->pWhen, 0); if( db->mallocFailed || sqlite3ResolveExprNames(&sNC, whenExpr) ){ pParse->trigStack = trigStackEntry.pNext; sqlite3ExprDelete(db, whenExpr); return 1; } sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, SQLITE_JUMPIFNULL); sqlite3ExprDelete(db, whenExpr); codeTriggerProgram(pParse, p->step_list, orconf); /* Pop the entry off the trigger stack */ pParse->trigStack = trigStackEntry.pNext; sqlite3AuthContextPop(&sContext); sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger); } } if( piOldColMask ) *piOldColMask |= trigStackEntry.oldColMask; if( piNewColMask ) *piNewColMask |= trigStackEntry.newColMask; return 0; }
/* ** Process an UPDATE statement. ** ** UPDATE OR IGNORE table_wxyz SET a=b, c=d WHERE e<5 AND f NOT NULL; ** \_______/ \________/ \______/ \________________/ * onError pTabList pChanges pWhere */ void sqlite3Update( Parse *pParse, /* The parser context */ SrcList *pTabList, /* The table in which we should change things */ ExprList *pChanges, /* Things to be changed */ Expr *pWhere, /* The WHERE clause. May be null */ int onError, /* How to handle constraint errors */ ExprList *pOrderBy, /* ORDER BY clause. May be null */ Expr *pLimit, /* LIMIT clause. May be null */ Upsert *pUpsert /* ON CONFLICT clause, or null */ ){ int i, j; /* Loop counters */ Table *pTab; /* The table to be updated */ int addrTop = 0; /* VDBE instruction address of the start of the loop */ WhereInfo *pWInfo; /* Information about the WHERE clause */ Vdbe *v; /* The virtual database engine */ Index *pIdx; /* For looping over indices */ Index *pPk; /* The PRIMARY KEY index for WITHOUT ROWID tables */ int nIdx; /* Number of indices that need updating */ int iBaseCur; /* Base cursor number */ int iDataCur; /* Cursor for the canonical data btree */ int iIdxCur; /* Cursor for the first index */ sqlite3 *db; /* The database structure */ int *aRegIdx = 0; /* First register in array assigned to each index */ int *aXRef = 0; /* aXRef[i] is the index in pChanges->a[] of the ** an expression for the i-th column of the table. ** aXRef[i]==-1 if the i-th column is not changed. */ u8 *aToOpen; /* 1 for tables and indices to be opened */ u8 chngPk; /* PRIMARY KEY changed in a WITHOUT ROWID table */ u8 chngRowid; /* Rowid changed in a normal table */ u8 chngKey; /* Either chngPk or chngRowid */ Expr *pRowidExpr = 0; /* Expression defining the new record number */ AuthContext sContext; /* The authorization context */ NameContext sNC; /* The name-context to resolve expressions in */ int iDb; /* Database containing the table being updated */ int eOnePass; /* ONEPASS_XXX value from where.c */ int hasFK; /* True if foreign key processing is required */ int labelBreak; /* Jump here to break out of UPDATE loop */ int labelContinue; /* Jump here to continue next step of UPDATE loop */ int flags; /* Flags for sqlite3WhereBegin() */ #ifndef SQLITE_OMIT_TRIGGER int isView; /* True when updating a view (INSTEAD OF trigger) */ Trigger *pTrigger; /* List of triggers on pTab, if required */ int tmask; /* Mask of TRIGGER_BEFORE|TRIGGER_AFTER */ #endif int newmask; /* Mask of NEW.* columns accessed by BEFORE triggers */ int iEph = 0; /* Ephemeral table holding all primary key values */ int nKey = 0; /* Number of elements in regKey for WITHOUT ROWID */ int aiCurOnePass[2]; /* The write cursors opened by WHERE_ONEPASS */ int addrOpen = 0; /* Address of OP_OpenEphemeral */ int iPk = 0; /* First of nPk cells holding PRIMARY KEY value */ i16 nPk = 0; /* Number of components of the PRIMARY KEY */ int bReplace = 0; /* True if REPLACE conflict resolution might happen */ /* Register Allocations */ int regRowCount = 0; /* A count of rows changed */ int regOldRowid = 0; /* The old rowid */ int regNewRowid = 0; /* The new rowid */ int regNew = 0; /* Content of the NEW.* table in triggers */ int regOld = 0; /* Content of OLD.* table in triggers */ int regRowSet = 0; /* Rowset of rows to be updated */ int regKey = 0; /* composite PRIMARY KEY value */ memset(&sContext, 0, sizeof(sContext)); db = pParse->db; if( pParse->nErr || db->mallocFailed ){ goto update_cleanup; } assert( pTabList->nSrc==1 ); /* Locate the table which we want to update. */ pTab = sqlite3SrcListLookup(pParse, pTabList); if( pTab==0 ) goto update_cleanup; iDb = sqlite3SchemaToIndex(pParse->db, pTab->pSchema); /* Figure out if we have any triggers and if the table being ** updated is a view. */ #ifndef SQLITE_OMIT_TRIGGER pTrigger = sqlite3TriggersExist(pParse, pTab, TK_UPDATE, pChanges, &tmask); isView = pTab->pSelect!=0; assert( pTrigger || tmask==0 ); #else # define pTrigger 0 # define isView 0 # define tmask 0 #endif #ifdef SQLITE_OMIT_VIEW # undef isView # define isView 0 #endif #ifdef SQLITE_ENABLE_UPDATE_DELETE_LIMIT if( !isView ){ pWhere = sqlite3LimitWhere( pParse, pTabList, pWhere, pOrderBy, pLimit, "UPDATE" ); pOrderBy = 0; pLimit = 0; } #endif if( sqlite3ViewGetColumnNames(pParse, pTab) ){ goto update_cleanup; } if( sqlite3IsReadOnly(pParse, pTab, tmask) ){ goto update_cleanup; } /* Allocate a cursors for the main database table and for all indices. ** The index cursors might not be used, but if they are used they ** need to occur right after the database cursor. So go ahead and ** allocate enough space, just in case. */ iBaseCur = iDataCur = pParse->nTab++; iIdxCur = iDataCur+1; pPk = HasRowid(pTab) ? 0 : sqlite3PrimaryKeyIndex(pTab); testcase( pPk!=0 && pPk!=pTab->pIndex ); for(nIdx=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, nIdx++){ if( pPk==pIdx ){ iDataCur = pParse->nTab; } pParse->nTab++; } if( pUpsert ){ /* On an UPSERT, reuse the same cursors already opened by INSERT */ iDataCur = pUpsert->iDataCur; iIdxCur = pUpsert->iIdxCur; pParse->nTab = iBaseCur; } pTabList->a[0].iCursor = iDataCur; /* Allocate space for aXRef[], aRegIdx[], and aToOpen[]. ** Initialize aXRef[] and aToOpen[] to their default values. */ aXRef = sqlite3DbMallocRawNN(db, sizeof(int) * (pTab->nCol+nIdx) + nIdx+2 ); if( aXRef==0 ) goto update_cleanup; aRegIdx = aXRef+pTab->nCol; aToOpen = (u8*)(aRegIdx+nIdx); memset(aToOpen, 1, nIdx+1); aToOpen[nIdx+1] = 0; for(i=0; i<pTab->nCol; i++) aXRef[i] = -1; /* Initialize the name-context */ memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; sNC.pSrcList = pTabList; sNC.uNC.pUpsert = pUpsert; sNC.ncFlags = NC_UUpsert; /* Resolve the column names in all the expressions of the ** of the UPDATE statement. Also find the column index ** for each column to be updated in the pChanges array. For each ** column to be updated, make sure we have authorization to change ** that column. */ chngRowid = chngPk = 0; for(i=0; i<pChanges->nExpr; i++){ if( sqlite3ResolveExprNames(&sNC, pChanges->a[i].pExpr) ){ goto update_cleanup; } for(j=0; j<pTab->nCol; j++){ if( sqlite3StrICmp(pTab->aCol[j].zName, pChanges->a[i].zName)==0 ){ if( j==pTab->iPKey ){ chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else if( pPk && (pTab->aCol[j].colFlags & COLFLAG_PRIMKEY)!=0 ){ chngPk = 1; } aXRef[j] = i; break; } } if( j>=pTab->nCol ){ if( pPk==0 && sqlite3IsRowid(pChanges->a[i].zName) ){ j = -1; chngRowid = 1; pRowidExpr = pChanges->a[i].pExpr; }else{ sqlite3ErrorMsg(pParse, "no such column: %s", pChanges->a[i].zName); pParse->checkSchema = 1; goto update_cleanup; } } #ifndef SQLITE_OMIT_AUTHORIZATION { int rc; rc = sqlite3AuthCheck(pParse, SQLITE_UPDATE, pTab->zName, j<0 ? "ROWID" : pTab->aCol[j].zName, db->aDb[iDb].zDbSName); if( rc==SQLITE_DENY ){ goto update_cleanup; }else if( rc==SQLITE_IGNORE ){ aXRef[j] = -1; } } #endif } assert( (chngRowid & chngPk)==0 ); assert( chngRowid==0 || chngRowid==1 ); assert( chngPk==0 || chngPk==1 ); chngKey = chngRowid + chngPk; /* The SET expressions are not actually used inside the WHERE loop. ** So reset the colUsed mask. Unless this is a virtual table. In that ** case, set all bits of the colUsed mask (to ensure that the virtual ** table implementation makes all columns available). */ pTabList->a[0].colUsed = IsVirtual(pTab) ? ALLBITS : 0; hasFK = sqlite3FkRequired(pParse, pTab, aXRef, chngKey); /* There is one entry in the aRegIdx[] array for each index on the table ** being updated. Fill in aRegIdx[] with a register number that will hold ** the key for accessing each index. */ if( onError==OE_Replace ) bReplace = 1; for(j=0, pIdx=pTab->pIndex; pIdx; pIdx=pIdx->pNext, j++){ int reg; if( chngKey || hasFK>1 || pIdx==pPk || indexWhereClauseMightChange(pIdx,aXRef,chngRowid) ){ reg = ++pParse->nMem; pParse->nMem += pIdx->nColumn; }else{ reg = 0; for(i=0; i<pIdx->nKeyCol; i++){ if( indexColumnIsBeingUpdated(pIdx, i, aXRef, chngRowid) ){ reg = ++pParse->nMem; pParse->nMem += pIdx->nColumn; if( onError==OE_Default && pIdx->onError==OE_Replace ){ bReplace = 1; } break; } } } if( reg==0 ) aToOpen[j+1] = 0; aRegIdx[j] = reg; } if( bReplace ){ /* If REPLACE conflict resolution might be invoked, open cursors on all ** indexes in case they are needed to delete records. */ memset(aToOpen, 1, nIdx+1); } /* Begin generating code. */ v = sqlite3GetVdbe(pParse); if( v==0 ) goto update_cleanup; if( pParse->nested==0 ) sqlite3VdbeCountChanges(v); sqlite3BeginWriteOperation(pParse, pTrigger || hasFK, iDb); /* Allocate required registers. */ if( !IsVirtual(pTab) ){ regRowSet = ++pParse->nMem; regOldRowid = regNewRowid = ++pParse->nMem; if( chngPk || pTrigger || hasFK ){ regOld = pParse->nMem + 1; pParse->nMem += pTab->nCol; } if( chngKey || pTrigger || hasFK ){ regNewRowid = ++pParse->nMem; } regNew = pParse->nMem + 1; pParse->nMem += pTab->nCol; } /* Start the view context. */ if( isView ){ sqlite3AuthContextPush(pParse, &sContext, pTab->zName); } /* If we are trying to update a view, realize that view into ** an ephemeral table. */ #if !defined(SQLITE_OMIT_VIEW) && !defined(SQLITE_OMIT_TRIGGER) if( isView ){ sqlite3MaterializeView(pParse, pTab, pWhere, pOrderBy, pLimit, iDataCur ); pOrderBy = 0; pLimit = 0; } #endif /* Resolve the column names in all the expressions in the ** WHERE clause. */ if( sqlite3ResolveExprNames(&sNC, pWhere) ){ goto update_cleanup; } #ifndef SQLITE_OMIT_VIRTUALTABLE /* Virtual tables must be handled separately */ if( IsVirtual(pTab) ){ updateVirtualTable(pParse, pTabList, pTab, pChanges, pRowidExpr, aXRef, pWhere, onError); goto update_cleanup; } #endif /* Jump to labelBreak to abandon further processing of this UPDATE */ labelContinue = labelBreak = sqlite3VdbeMakeLabel(pParse); /* Not an UPSERT. Normal processing. Begin by ** initialize the count of updated rows */ if( (db->flags&SQLITE_CountRows)!=0 && !pParse->pTriggerTab && !pParse->nested && pUpsert==0 ){ regRowCount = ++pParse->nMem; sqlite3VdbeAddOp2(v, OP_Integer, 0, regRowCount); } if( HasRowid(pTab) ){ sqlite3VdbeAddOp3(v, OP_Null, 0, regRowSet, regOldRowid); }else{ assert( pPk!=0 ); nPk = pPk->nKeyCol; iPk = pParse->nMem+1; pParse->nMem += nPk; regKey = ++pParse->nMem; if( pUpsert==0 ){ iEph = pParse->nTab++; sqlite3VdbeAddOp3(v, OP_Null, 0, iPk, iPk+nPk-1); addrOpen = sqlite3VdbeAddOp2(v, OP_OpenEphemeral, iEph, nPk); sqlite3VdbeSetP4KeyInfo(pParse, pPk); } } if( pUpsert ){ /* If this is an UPSERT, then all cursors have already been opened by ** the outer INSERT and the data cursor should be pointing at the row ** that is to be updated. So bypass the code that searches for the ** row(s) to be updated. */ pWInfo = 0; eOnePass = ONEPASS_SINGLE; sqlite3ExprIfFalse(pParse, pWhere, labelBreak, SQLITE_JUMPIFNULL); }else{ /* Begin the database scan. ** ** Do not consider a single-pass strategy for a multi-row update if ** there are any triggers or foreign keys to process, or rows may ** be deleted as a result of REPLACE conflict handling. Any of these ** things might disturb a cursor being used to scan through the table ** or index, causing a single-pass approach to malfunction. */ flags = WHERE_ONEPASS_DESIRED|WHERE_SEEK_UNIQ_TABLE; if( !pParse->nested && !pTrigger && !hasFK && !chngKey && !bReplace ){ flags |= WHERE_ONEPASS_MULTIROW; } pWInfo = sqlite3WhereBegin(pParse, pTabList, pWhere, 0, 0, flags, iIdxCur); if( pWInfo==0 ) goto update_cleanup; /* A one-pass strategy that might update more than one row may not ** be used if any column of the index used for the scan is being ** updated. Otherwise, if there is an index on "b", statements like ** the following could create an infinite loop: ** ** UPDATE t1 SET b=b+1 WHERE b>? ** ** Fall back to ONEPASS_OFF if where.c has selected a ONEPASS_MULTI ** strategy that uses an index for which one or more columns are being ** updated. */ eOnePass = sqlite3WhereOkOnePass(pWInfo, aiCurOnePass); if( eOnePass!=ONEPASS_SINGLE ){ sqlite3MultiWrite(pParse); if( eOnePass==ONEPASS_MULTI ){ int iCur = aiCurOnePass[1]; if( iCur>=0 && iCur!=iDataCur && aToOpen[iCur-iBaseCur] ){ eOnePass = ONEPASS_OFF; } assert( iCur!=iDataCur || !HasRowid(pTab) ); } } } if( HasRowid(pTab) ){ /* Read the rowid of the current row of the WHERE scan. In ONEPASS_OFF ** mode, write the rowid into the FIFO. In either of the one-pass modes, ** leave it in register regOldRowid. */ sqlite3VdbeAddOp2(v, OP_Rowid, iDataCur, regOldRowid); if( eOnePass==ONEPASS_OFF ){ sqlite3VdbeAddOp2(v, OP_RowSetAdd, regRowSet, regOldRowid); } }else{ /* Read the PK of the current row into an array of registers. In ** ONEPASS_OFF mode, serialize the array into a record and store it in ** the ephemeral table. Or, in ONEPASS_SINGLE or MULTI mode, change ** the OP_OpenEphemeral instruction to a Noop (the ephemeral table ** is not required) and leave the PK fields in the array of registers. */ for(i=0; i<nPk; i++){ assert( pPk->aiColumn[i]>=0 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur,pPk->aiColumn[i],iPk+i); } if( eOnePass ){ if( addrOpen ) sqlite3VdbeChangeToNoop(v, addrOpen); nKey = nPk; regKey = iPk; }else{ sqlite3VdbeAddOp4(v, OP_MakeRecord, iPk, nPk, regKey, sqlite3IndexAffinityStr(db, pPk), nPk); sqlite3VdbeAddOp4Int(v, OP_IdxInsert, iEph, regKey, iPk, nPk); } } if( pUpsert==0 ){ if( eOnePass!=ONEPASS_MULTI ){ sqlite3WhereEnd(pWInfo); } if( !isView ){ int addrOnce = 0; /* Open every index that needs updating. */ if( eOnePass!=ONEPASS_OFF ){ if( aiCurOnePass[0]>=0 ) aToOpen[aiCurOnePass[0]-iBaseCur] = 0; if( aiCurOnePass[1]>=0 ) aToOpen[aiCurOnePass[1]-iBaseCur] = 0; } if( eOnePass==ONEPASS_MULTI && (nIdx-(aiCurOnePass[1]>=0))>0 ){ addrOnce = sqlite3VdbeAddOp0(v, OP_Once); VdbeCoverage(v); } sqlite3OpenTableAndIndices(pParse, pTab, OP_OpenWrite, 0, iBaseCur, aToOpen, 0, 0); if( addrOnce ) sqlite3VdbeJumpHere(v, addrOnce); } /* Top of the update loop */ if( eOnePass!=ONEPASS_OFF ){ if( !isView && aiCurOnePass[0]!=iDataCur && aiCurOnePass[1]!=iDataCur ){ assert( pPk ); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelBreak, regKey,nKey); VdbeCoverage(v); } if( eOnePass!=ONEPASS_SINGLE ){ labelContinue = sqlite3VdbeMakeLabel(pParse); } sqlite3VdbeAddOp2(v, OP_IsNull, pPk ? regKey : regOldRowid, labelBreak); VdbeCoverageIf(v, pPk==0); VdbeCoverageIf(v, pPk!=0); }else if( pPk ){ labelContinue = sqlite3VdbeMakeLabel(pParse); sqlite3VdbeAddOp2(v, OP_Rewind, iEph, labelBreak); VdbeCoverage(v); addrTop = sqlite3VdbeAddOp2(v, OP_RowData, iEph, regKey); sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue, regKey, 0); VdbeCoverage(v); }else{ labelContinue = sqlite3VdbeAddOp3(v, OP_RowSetRead, regRowSet,labelBreak, regOldRowid); VdbeCoverage(v); sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } } /* If the rowid value will change, set register regNewRowid to ** contain the new value. If the rowid is not being modified, ** then regNewRowid is the same register as regOldRowid, which is ** already populated. */ assert( chngKey || pTrigger || hasFK || regOldRowid==regNewRowid ); if( chngRowid ){ sqlite3ExprCode(pParse, pRowidExpr, regNewRowid); sqlite3VdbeAddOp1(v, OP_MustBeInt, regNewRowid); VdbeCoverage(v); } /* Compute the old pre-UPDATE content of the row being changed, if that ** information is needed */ if( chngPk || hasFK || pTrigger ){ u32 oldmask = (hasFK ? sqlite3FkOldmask(pParse, pTab) : 0); oldmask |= sqlite3TriggerColmask(pParse, pTrigger, pChanges, 0, TRIGGER_BEFORE|TRIGGER_AFTER, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( oldmask==0xffffffff || (i<32 && (oldmask & MASKBIT32(i))!=0) || (pTab->aCol[i].colFlags & COLFLAG_PRIMKEY)!=0 ){ testcase( oldmask!=0xffffffff && i==31 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regOld+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regOld+i); } } if( chngRowid==0 && pPk==0 ){ sqlite3VdbeAddOp2(v, OP_Copy, regOldRowid, regNewRowid); } } /* Populate the array of registers beginning at regNew with the new ** row data. This array is used to check constants, create the new ** table and index records, and as the values for any new.* references ** made by triggers. ** ** If there are one or more BEFORE triggers, then do not populate the ** registers associated with columns that are (a) not modified by ** this UPDATE statement and (b) not accessed by new.* references. The ** values for registers not modified by the UPDATE must be reloaded from ** the database after the BEFORE triggers are fired anyway (as the trigger ** may have modified them). So not loading those that are not going to ** be used eliminates some redundant opcodes. */ newmask = sqlite3TriggerColmask( pParse, pTrigger, pChanges, 1, TRIGGER_BEFORE, pTab, onError ); for(i=0; i<pTab->nCol; i++){ if( i==pTab->iPKey ){ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); }else{ j = aXRef[i]; if( j>=0 ){ sqlite3ExprCode(pParse, pChanges->a[j].pExpr, regNew+i); }else if( 0==(tmask&TRIGGER_BEFORE) || i>31 || (newmask & MASKBIT32(i)) ){ /* This branch loads the value of a column that will not be changed ** into a register. This is done if there are no BEFORE triggers, or ** if there are one or more BEFORE triggers that use this value via ** a new.* reference in a trigger program. */ testcase( i==31 ); testcase( i==32 ); sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i); }else{ sqlite3VdbeAddOp2(v, OP_Null, 0, regNew+i); } } } /* Fire any BEFORE UPDATE triggers. This happens before constraints are ** verified. One could argue that this is wrong. */ if( tmask&TRIGGER_BEFORE ){ sqlite3TableAffinity(v, pTab, regNew); sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_BEFORE, pTab, regOldRowid, onError, labelContinue); /* The row-trigger may have deleted the row being updated. In this ** case, jump to the next row. No updates or AFTER triggers are ** required. This behavior - what happens when the row being updated ** is deleted or renamed by a BEFORE trigger - is left undefined in the ** documentation. */ if( pPk ){ sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, labelContinue,regKey,nKey); VdbeCoverage(v); }else{ sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, labelContinue, regOldRowid); VdbeCoverage(v); } /* After-BEFORE-trigger-reload-loop: ** If it did not delete it, the BEFORE trigger may still have modified ** some of the columns of the row being updated. Load the values for ** all columns not modified by the update statement into their registers ** in case this has happened. Only unmodified columns are reloaded. ** The values computed for modified columns use the values before the ** BEFORE trigger runs. See test case trigger1-18.0 (added 2018-04-26) ** for an example. */ for(i=0; i<pTab->nCol; i++){ if( aXRef[i]<0 && i!=pTab->iPKey ){ sqlite3ExprCodeGetColumnOfTable(v, pTab, iDataCur, i, regNew+i); } } } if( !isView ){ int addr1 = 0; /* Address of jump instruction */ /* Do constraint checks. */ assert( regOldRowid>0 ); sqlite3GenerateConstraintChecks(pParse, pTab, aRegIdx, iDataCur, iIdxCur, regNewRowid, regOldRowid, chngKey, onError, labelContinue, &bReplace, aXRef, 0); /* Do FK constraint checks. */ if( hasFK ){ sqlite3FkCheck(pParse, pTab, regOldRowid, 0, aXRef, chngKey); } /* Delete the index entries associated with the current record. */ if( bReplace || chngKey ){ if( pPk ){ addr1 = sqlite3VdbeAddOp4Int(v, OP_NotFound, iDataCur, 0, regKey, nKey); }else{ addr1 = sqlite3VdbeAddOp3(v, OP_NotExists, iDataCur, 0, regOldRowid); } VdbeCoverageNeverTaken(v); } sqlite3GenerateRowIndexDelete(pParse, pTab, iDataCur, iIdxCur, aRegIdx, -1); /* If changing the rowid value, or if there are foreign key constraints ** to process, delete the old record. Otherwise, add a noop OP_Delete ** to invoke the pre-update hook. ** ** That (regNew==regnewRowid+1) is true is also important for the ** pre-update hook. If the caller invokes preupdate_new(), the returned ** value is copied from memory cell (regNewRowid+1+iCol), where iCol ** is the column index supplied by the user. */ assert( regNew==regNewRowid+1 ); #ifdef SQLITE_ENABLE_PREUPDATE_HOOK sqlite3VdbeAddOp3(v, OP_Delete, iDataCur, OPFLAG_ISUPDATE | ((hasFK>1 || chngKey) ? 0 : OPFLAG_ISNOOP), regNewRowid ); if( eOnePass==ONEPASS_MULTI ){ assert( hasFK==0 && chngKey==0 ); sqlite3VdbeChangeP5(v, OPFLAG_SAVEPOSITION); } if( !pParse->nested ){ sqlite3VdbeAppendP4(v, pTab, P4_TABLE); } #else if( hasFK>1 || chngKey ){ sqlite3VdbeAddOp2(v, OP_Delete, iDataCur, 0); } #endif if( bReplace || chngKey ){ sqlite3VdbeJumpHere(v, addr1); } if( hasFK ){ sqlite3FkCheck(pParse, pTab, 0, regNewRowid, aXRef, chngKey); } /* Insert the new index entries and the new record. */ sqlite3CompleteInsertion( pParse, pTab, iDataCur, iIdxCur, regNewRowid, aRegIdx, OPFLAG_ISUPDATE | (eOnePass==ONEPASS_MULTI ? OPFLAG_SAVEPOSITION : 0), 0, 0 ); /* Do any ON CASCADE, SET NULL or SET DEFAULT operations required to ** handle rows (possibly in other tables) that refer via a foreign key ** to the row just updated. */ if( hasFK ){ sqlite3FkActions(pParse, pTab, pChanges, regOldRowid, aXRef, chngKey); } } /* Increment the row counter */ if( regRowCount ){ sqlite3VdbeAddOp2(v, OP_AddImm, regRowCount, 1); } sqlite3CodeRowTrigger(pParse, pTrigger, TK_UPDATE, pChanges, TRIGGER_AFTER, pTab, regOldRowid, onError, labelContinue); /* Repeat the above with the next record to be updated, until ** all record selected by the WHERE clause have been updated. */ if( eOnePass==ONEPASS_SINGLE ){ /* Nothing to do at end-of-loop for a single-pass */ }else if( eOnePass==ONEPASS_MULTI ){ sqlite3VdbeResolveLabel(v, labelContinue); sqlite3WhereEnd(pWInfo); }else if( pPk ){ sqlite3VdbeResolveLabel(v, labelContinue); sqlite3VdbeAddOp2(v, OP_Next, iEph, addrTop); VdbeCoverage(v); }else{ sqlite3VdbeGoto(v, labelContinue); } sqlite3VdbeResolveLabel(v, labelBreak); /* Update the sqlite_sequence table by storing the content of the ** maximum rowid counter values recorded while inserting into ** autoincrement tables. */ if( pParse->nested==0 && pParse->pTriggerTab==0 && pUpsert==0 ){ sqlite3AutoincrementEnd(pParse); } /* ** Return the number of rows that were changed, if we are tracking ** that information. */ if( regRowCount ){ sqlite3VdbeAddOp2(v, OP_ResultRow, regRowCount, 1); sqlite3VdbeSetNumCols(v, 1); sqlite3VdbeSetColName(v, 0, COLNAME_NAME, "rows updated", SQLITE_STATIC); } update_cleanup: sqlite3AuthContextPop(&sContext); sqlite3DbFree(db, aXRef); /* Also frees aRegIdx[] and aToOpen[] */ sqlite3SrcListDelete(db, pTabList); sqlite3ExprListDelete(db, pChanges); sqlite3ExprDelete(db, pWhere); #if defined(SQLITE_ENABLE_UPDATE_DELETE_LIMIT) sqlite3ExprListDelete(db, pOrderBy); sqlite3ExprDelete(db, pLimit); #endif return; }
/* ** This is called to code FOR EACH ROW triggers. ** ** When the code that this function generates is executed, the following ** must be true: ** ** 1. No cursors may be open in the main database. (But newIdx and oldIdx ** can be indices of cursors in temporary tables. See below.) ** ** 2. If the triggers being coded are ON INSERT or ON UPDATE triggers, then ** a temporary vdbe cursor (index newIdx) must be open and pointing at ** a row containing values to be substituted for new.* expressions in the ** trigger program(s). ** ** 3. If the triggers being coded are ON DELETE or ON UPDATE triggers, then ** a temporary vdbe cursor (index oldIdx) must be open and pointing at ** a row containing values to be substituted for old.* expressions in the ** trigger program(s). ** */ int sqlite3CodeRowTrigger( Parse *pParse, /* Parse context */ int op, /* One of TK_UPDATE, TK_INSERT, TK_DELETE */ ExprList *pChanges, /* Changes list for any UPDATE OF triggers */ int tr_tm, /* One of TRIGGER_BEFORE, TRIGGER_AFTER */ Table *pTab, /* The table to code triggers from */ int newIdx, /* The indice of the "new" row to access */ int oldIdx, /* The indice of the "old" row to access */ int orconf, /* ON CONFLICT policy */ int ignoreJump /* Instruction to jump to for RAISE(IGNORE) */ ){ Trigger *pTrigger; TriggerStack *pStack; TriggerStack trigStackEntry; assert(op == TK_UPDATE || op == TK_INSERT || op == TK_DELETE); assert(tr_tm == TRIGGER_BEFORE || tr_tm == TRIGGER_AFTER ); assert(newIdx != -1 || oldIdx != -1); pTrigger = pTab->pTrigger; while( pTrigger ){ int fire_this = 0; /* determine whether we should code this trigger */ if( pTrigger->op == op && pTrigger->tr_tm == tr_tm ){ fire_this = 1; for(pStack=pParse->trigStack; pStack; pStack=pStack->pNext){ if( pStack->pTrigger==pTrigger ){ fire_this = 0; } } if( op == TK_UPDATE && pTrigger->pColumns && !checkColumnOverLap(pTrigger->pColumns, pChanges) ){ fire_this = 0; } } if( fire_this ){ int endTrigger; Expr * whenExpr; AuthContext sContext; NameContext sNC; memset(&sNC, 0, sizeof(sNC)); sNC.pParse = pParse; /* Push an entry on to the trigger stack */ trigStackEntry.pTrigger = pTrigger; trigStackEntry.newIdx = newIdx; trigStackEntry.oldIdx = oldIdx; trigStackEntry.pTab = pTab; trigStackEntry.pNext = pParse->trigStack; trigStackEntry.ignoreJump = ignoreJump; pParse->trigStack = &trigStackEntry; sqlite3AuthContextPush(pParse, &sContext, pTrigger->name); /* code the WHEN clause */ endTrigger = sqlite3VdbeMakeLabel(pParse->pVdbe); whenExpr = sqlite3ExprDup(pTrigger->pWhen); if( sqlite3ExprResolveNames(&sNC, whenExpr) ){ pParse->trigStack = trigStackEntry.pNext; sqlite3ExprDelete(whenExpr); return 1; } sqlite3ExprIfFalse(pParse, whenExpr, endTrigger, 1); sqlite3ExprDelete(whenExpr); codeTriggerProgram(pParse, pTrigger->step_list, orconf); /* Pop the entry off the trigger stack */ pParse->trigStack = trigStackEntry.pNext; sqlite3AuthContextPop(&sContext); sqlite3VdbeResolveLabel(pParse->pVdbe, endTrigger); } pTrigger = pTrigger->pNext; } return 0; }